Bill a window cleaner's monthly round with add-on jobs, no-access call-outs, a direct debit discount and a minimum charge

# Bill a window cleaner's round for March Inputs: `visits.csv` (each visit: customer, date, house type, extras separated by `;`, outcome), `customers.json` (each customer's payment method) and `prices.json` (house-type prices, extra prices and the monthly minimum). Every amount is in pounds. Billing rules: - A cleaned visit (outcome cleaned) costs the house-type price plus the price of each listed extra, less 2.00 if the customer pays by direct_debit. - A no-access visit (outcome no_access) is charged a call-out of 50% of the house-type price (rounded to the cent half-up), with no extras and no direct debit discount. - If a customer's visits for the month add up to less than the monthly_minimum, add a top-up so the month comes to the minimum; the minimum applies per customer per month, not per visit. Write `out/round.json`: `{"visit_price": {"<visit_id>": <price>, ...}, "top_up": {"<customer>": <top-up, 0 if none>, ...}, "due": {"<customer>": <visits + top-up>, ...}, "grand_total": <sum of due>}` with every visit and every customer in `visits.csv`. ## How this run works - Work on your own: nobody will answer questions in this task, and writing to `ask/` counts against the run. - Write only under `out/`. Create `out/` if it is missing. Inputs are synthetic; don't fetch anything from the network. - Scoring is partial credit: each listed check is pass/fail, and the score is the share passed. Numbers are compared to within 0.005 unless the task says otherwise.